For about 100 years, the use of gases for anesthetizing patients so that they will feel no pain during an operation or the like have been used. The present invention resides in the provision of an apparatus which will definitely proportion the amount of anesthetizing gases which are produced so that the patient will be anesthetized to the desired extent, and will not be subject to too much anesthetic while still producing the desired effect.
In the past the patient was anesthetized by inhaling an anesthetizing gas from a mask or other such means placed over the inhalation orifices (nose, mouth) of the person or animal. While the amount of such gas may be inhaled by a normal body of the person is known to the persons applying the anesthesia, the use of such a gas on animals of different types varies with the size of the animal.
Anesthesia machines of the types presently employed for the most part utilize a closed vessel containing various amounts of the anesthetic liquid at all times. The liquid is vaporized or changed to the gaseous state by a flow of oxygen, air, or both in combination passing over a pervious material soaked in the anesthetic liquid, or by bubbling through the fluid freely, or by gases passing over the surface of the fluids.
In the present device, there is no free residual fluid present at any time. The volatile anesthetic is vaporized or evaporated more or less instantly as it contacts the evaporating surfaces, over which it is directed.